Car Stuck! Engine Coolant boiling over

[John Larson]

SJ said:  "My hunch is a stuck thermostat.
I will pick up a new thermostat and gasket and go to where the car is stuck
and attempt replacing the thermostat in the parking lot."

I can't remember seeing a stuck thermostat on a 5K, and I've worked on them
since '78.  I'd look at the fan switch, and the cap as well.  Unplug the
switch and jump the wires, 2 at a time, making sure the rest of the circuit
works.  The resistor blocks fail pretty often.  If the fan works when you
jumper the wires, then you need to plug  the wires back in and run it 'til
it's hot.  Feel the radiator, top and bottom.  It should get hot along with
the engine.  If it gets hot and the fan doesn't come on, cool it off and
change the fan switch.  It's cheap, a service item, and isn't that hard to
do. Get the standard temperature part.  Takes a 29 mm deep socket to change
it, although there are other wrenches that may work.  Be careful how you
apply the force, it's easy to break the radiator.  If that doesn't fix it,
check the resistor block on the frame rail below and in front of the
radiator.  Harder to get at, costs a bunch.  If the radiator doesn't get hot
with the engine, THEN you look at the thermostat.  Check the cap for
pressure.  It needs to hold pressure to keep the cooling system from boiling
over.  HTH, John